consider first number is = x
formula, 
(n / 2)(first number + last number) = sum, 
7/2(x+x+6)= 945
2x+6= 945×2/7
2x+6 = 270
2x= 270-6
x=264/2= 132
Answer the smallest number is 132.
 
        
             
        
        
        
Line:
3x+y=7
y=-3x+7
Slope of Perpendicular Line: 1/3x
For the perpendicular line to contain point (6,-1) the y-intercept would be (0,1), thus the equation of the line would be y=1/3x+1
y=1/3x+1
        
             
        
        
        
??? The answer is not able to be found for the fact that there are 3 numbers all coming from x.